The Mekhilta articulates one of the most powerful principles in all of rabbinic theology through a deceptively simple logical argument. The principle: God's capacity for good always exceeds His capacity for punishment.
The argument begins with an observation about divine justice. When God punishes, He punishes the instigator first. The one who initiated the transgression bears the first blow. This is the pattern throughout Scripture — the serpent is cursed before Adam, Egypt's gods are struck before Egypt's people, the ringleaders fall before the followers.
Now the Mekhilta applies its kal va'chomer — its argument from lesser to greater. Punishment is God's "lesser measure." It is not what He prefers. It is not His default mode. Beneficence — reward, blessing, mercy — is His "greater measure." It is the dominant force in the universe. If even in the lesser measure of punishment, the initiator is addressed first, then how much more so in the greater measure of beneficence must the initiator of a mitzvah be rewarded first!
The implications cascade outward. The person who starts a charitable initiative receives blessing before those who follow. The one who begins a tradition of prayer, of study, of kindness, stands first in line for divine reward. Priority in punishment establishes priority in reward — and since God's generosity is always greater than His severity, the reward for initiating good must vastly exceed the punishment for initiating evil.
This is the Mekhilta's optimistic theology in its purest form. The universe is tilted toward mercy. The scales are rigged in favor of those who act first for good.